It seems like eSports is a massive growth industry and we are still in the very early days of it. I think the reason we see so many of the older games like counter strike and league of legends, as opposed to many of the newer games (e.g. call of duty) on betting sites basically comes down to cheating. We're unlikely to see much sports betting going on outside of highly regulated arena style games, where players have to use host provided machines that cannot be interfered with in order to make sure everyone is playing fairly. Covid would actually have put this whole scene on ice for a while because it's so easy to modify and introduce hacks to machines at "home" that would be untraceable but wildly rig the game in a cheaters favor.